Postpartum relapse rates among women who quit smoking during pregnancy are exceedingly high (i.e., approximately 45 percent at 2-3 months postpartum, 60-70 percent at 6 months, and up to 80 percent at one year). These high rates of postpartum relapse are surprising because they occur in a population where the majority of women have been abstinent for 7-9 months prior to giving birth. Thus, the tremendous public health opportunity to facilitate long-term abstinence from tobacco among mothers as well as reduce the detrimental effects on smoking on their children is not being fully realized. The overall aim of this project is to develop and evaluate a "Motivational Relapse Prevention" (MRP) treatment for reducing postpartum smoking relapse among women who quit during pregnancy. MRP will utilize a motivational enhancement approach that specifically targets increasing commitment and intrinsic motives for maintaining postpartum abstinence, relapse prevention theory constructs (i.e., self-efficacy, outcome expectancies, coping behavior), and issues of particular relevance to postpartum women (e.g., negative affect, stress, social support, weight concerns). Treatment will be telephone-based and is designed to be easily disseminated to population-based settings for tobacco control (e.g., state quitlines, health care systems). In addition, the project will assess the cost-effectiveness of MRP. Participants (N=400) will be randomly assigned to one of two groups: 1) Standard Relapse Prevention, or 2) MRP. MRP will consist of six telephone counseling calls, and relapse prevention self-help materials designed specifically for the postpartum period. Postpartum assessments will occur at weeks 8, 26, and 52.